Birth. Ca. 1290, Milan. Third of the ten children of Matteo I Magno Visconti, prince of Milan, and Bonacosa Borri. The other sibling were Galeazzo I, Marco, Luchino I, Stefano, Caterina, Zaccarina, Floramonda, Agnese and Beatrice.

Education. He was destined to the ecclesiastical state, expecting to occupy a leading position in the Milanese Church (1). He received his formation at a studium generale in Milan.

Early life. In 1303, he obtained a canonicate in the cathedral of Lincoln, England, granted by Pope Benedict IX. He participated in the Council of Vienne in 1312, together with Isnardo Tacconi, titular patriarch of Antioch and administrator of Pavia. He appears as canon of the cathedral chapter of Milan for the first time on February 19, 1317. Abbot of S. Ambrogio, Milan. He had two illegitimate children, Leonardo and Margherita Visconti.

Episcopate. In 1317, the metropolitan cathedral chapter of Milan elected him archbishop. Pope John XXII did not confirm the election. The pope named instead Aircardus Antimiani as archbishop. Giovanni administered de facto the archdiocese of Milan as the legitimate archbishop was impeded most of the time and died in August 1339. In 1324, he was named provost of the large and rich church of Pontirolo. Shortly after, Pope John XXII excommunicated Giovanni, who had been accused of heresy. He was removed from his new post in Pontirolo. Giovanni allied himself with Antipope Nicholas V.

Cardinalate. Created pseudocardinal deacon of S. Eusebio in the consistory of January 19 (or 20), 1329. He made his submission to Pope John XXII by procurator on September 15, 1329, and in person on November 26, 1329; he was never promoted to the cardinalate by a legitimate pope. Elected bishop of Novara, August 1, 1331. On November 20, 1331, received permission to prorogate his episcopal consecration. Consecrated between December 23, 1331 and May 18, 1332. After the death of Archbishop Antimiani, Giovanni was again elected archbishop by the metropolitan cathedral chapter. He was confirmed by Pope Clement VI on July 17, 1342 and occupied the see until his death. Co-signore of Milan, together with is brother Luchino, from August 1339; at the death of the latter in January 1349, Giovanni became signore of Milan; his work was very important in the expansion and organization of the Milanese state. He obtained Bologna in October 1350; by a compromise with the Holy See, in 1352, he ceded his signoria over the city in exchange to becoming papal legate to the same for twelve years. He became signore of Genoa and of Novara in 1353.

Death. October 5, 1354, Milan. Buried in the metropolitan cathedral of Milan, together with Archbishop Ottorino Visconti of Milan; his monument was sculpted by an anonymous Campionese master; it originally was in the church of S. Tecla, Milan; a Latin poem is sculpted on it, signed by a Sabino de' Zamorei, from Parma, and dated 1354.

(1) This is according to Cadili, Giovanni Visconti, arcivescovo di Milano (1342-1354), p. 29. His second biography in Italian (Treccani), linled above, says that he initially persued a military career until 1316 and that then, following his father's wishes, he entered the ecclesiastical life.